What are your thoughts on the idea of cutting back on certain ingredients in a dessert so it won't be so fattening?

Eons ago my girlfriend used to make these awesome cookies at Christmas. It’s been 25 years since I had them so around Christmas time I got ahold of her to get the recipe.

I almost never make desserts (too many useless calories) so I was really looking forward to them. However, when I made them something was missing….something wasn’t right. It wasn’t like what I remembered. in fact, I didn’t eat more than 2 because they just weren’t right.
Then I noticed that it called for a cup of real butter, but only ½ a cup of sugar. I asked about that and she said yes, the original called for a full cup of sugar but she cut that in half so they wouldn’t be so fattening…... ?

I’m making them again today, using a full cup of sugar.

What do you think?